Fibre products such as for example egg cartons can be made from stock in a process where a fibre layer is created and shaped to a desired form whereby the so shaped fibre product is dewatered and possibly subjected to some form of post-processing operation.
U.S. Pat. No. 6,136,150 discloses a method for producing a flow stock in a mould tank. The moulding tank is used for producing a fibre product such as an egg carton or other packaging products. At least one horizontally extending grating is provided across the tank between the bottom and the brim of said tank. A flow of stock in the mould tank is pumped in at the bottom of the mould tank and is allowed to flow up over the brim of the tank resulting in a flow directed upwards important for forming a fibre layer of even thickness on a male tool which is dipped into said stock. Due to this arrangement stock is easily clogged in the tank at said grating or gratings. There is involved a lot of measures to get rid of such clogged portions of the stock which are both time consuming and expensive.
During production of fibre products such as for example egg boxes and drinking cups, it is desirable that the shape of the final product can be controlled in a reliable way. For many applications, it is also desirable that the final product has substantially even strength properties so that the final product does not bend easier in one direction than in another. If heat is used to dewater the fibre product, it is also desirable that the heat does not burn the surface of the fibre product. It is also desirable that vaporized water can be evacuated efficiently.
It is an object of the present invention to provide a tank assembly of the type defined above which set aside the above problems.